Telecine with dual digitizers and multiple scanning beams

ABSTRACT

The present invention teaches an improved parallel telecine for converting a plurality of recorded images or frames of film, defined by a first and a second set of frames of film, to a digital data stream. The improved telecine comprises a plurality of image transfer or digitizing systems for respectively digitizing each of the recorded images or frames of film or groupings of frames of film. Each image transfer and digitizing system comprises an illuminator system for illuminating the respective frames or groupings of frames, and a camera system for converting the image of the respective frame or groupings of frames into a digital data stream. Each camera sensor additionally comprises a position sensor for detecting a first and a second pair of edges on a coordinated positional tag at the edge of the film frame. Further, each camera system comprises an aligning mechanism for aligning each camera system in response to the set of edges of the respective coordinated position tag detected by the position sensor.

This application is a divisional of prior application U.S. Ser. No.09/036,347 filed Mar. 6, 1998, which is a divisional application of U.S.Ser. No. 08/384,998, filed Feb. 7, 1995, now U.S. Pat. No. 5,808,669.

TECHNICAL FIELD

This invention relates to the field of telecines, and more particularly,to a system and method for digitizing recorded images.

BACKGROUND ART

New technologies are for the first time making the concept of digitizingfull-length feature films feasible using an instrument known in the filmindustry as a telecine. Originally, the conversion from recorded film toan electronic format was realized in a process essentially analogous totelevision recording. Recorded film was first uniformly illuminated andthe image frames then recorded using a conventional television imagetube. In a similar approach, the film frames were scanned by imaging aCRT onto each frame, while recording the output intensity.

With the advent of analog-to-digital (A/D) converter technology,transforming image signals in real time and performing image processinghas become more viable. However, until the development of commerciallycost effective, high density digital storage media, the image output hadto be reconverted back to analog form for recording.

Further improvement has been obtained in the digitization process ofrecorded films with the maturation of high quality solid statedetectors. One such detector is a Charge Coupled Device ("CCD") array.Having increased sensitivity, CCD arrays enable several featuresincluding frame capturing. CCDs also decouple the A/D conversionprocess, with the exposure and readout steps being executed as separateprocedures.

Together with high performance processing and digital storage advances,the state-of-the-art of telecine has now advanced to The Cineon® systemby Kodak®. This known telecine design captures digital film informationat near film-grain resolution, allows image manipulation using digitalworkstations, and stores the results on digital tape.

The Cineon® system, however, has several shortcomings. It is relativelyslow with respect to the capture and storage of images. In this regard,one of the bottlenecks of the system can be found in the telecine imageconversion system, which utilizes a single trilinear CCD array for imagecapture. Various additional improvements may also be incorporated, toimprove the system's performance, including conversion from film todigital form, manipulation and correction of the digital imagery,compression of the resulting data stream, and storage on ahigh-capacity, low error rate electronic medium.

Thus, a need exists for an improved telecine having a higher conversionaccuracy at a lower cost. Further, a demand remains for an improvedtelecine having a higher throughput without multiport pattern noise.Moreover, an improved telecine is also of interest to industry which haslower speed film handling to thereby reduce the risks associated withthe digital conversion of valuable archival master recordings. There isa further demand for an improved telecine having a longer dwell time perframe enabling the use of slower optical components and thereby reducingcost. Similarly, an improved telecine having a maximized uniform frameillumination is also needed by industry for reducing post acquisitionprocessing. Finally, an improved telecine which records exposureconditions, as well as the state of the recording equipment and film,along with the actual image data, is of great interest to industry fordigital archiving purposes.

DISCLOSURE OF THE INVENTION

The primary advantage of the present invention is to provide an improvedtelecine which overcomes the limitations of the known art.

A further advantage of the present invention is to provide an improvedtelecine having a higher conversion accuracy at a lower cost.

Still another advantage of the present invention is to provide animproved telecine having a higher throughput without multiport patternnoise.

Yet another advantage of the present invention is to provide an improvedtelecine having lower speed film handling, thereby reducing the riskassociated with the digital conversion of valuable archival masterrecordings.

Yet still another advantage of the present invention is to provide animproved telecine having a longer dwell time per frame enabling the useof slower optical components and thereby reducing cost.

Yet still another advantage of the present invention is to provide animproved telecine having a maximized uniform frame illumination, therebyreducing post acquisition processing.

Yet still another advantage of the present invention is to provide animproved telecine capable of recording the exposure conditions, as wellas the state of the recording equipment and film, along with the actualimage data.

In order to achieve the advantages of the present invention, an improvedtelecine is disclosed for the simultaneous parallel conversion of aplurality of recorded images or frames of film or groupings of frames offilm into a digital data stream. The improved telecine comprises aplurality of image transfer or digitizing systems for respectivelydigitizing each of the recorded images or frames of film or groupings offrames of film. Each image transfer and digitizing system comprises anilluminator system for illuminating the respective frames or groupingsof frames, and a camera system for converting the image of therespective frame or groupings of frames into a digital data stream. Eachcamera sensor additionally comprises a position sensor for detecting afirst, second, third and fourth edge of a coordinated positional tag oneach recorded image of the film frame. Further, each camera systemcomprises an aligning mechanism for aligning each camera system inresponse to the set of edges of the respective coordinated position tagdetected by the position sensor.

In a further embodiment of the invention, an improved telecine isdisclosed for the simultaneous parallel conversion of a plurality ofrecorded images or frames of film or groupings of frames of film into adigital data stream. The improved telecine comprises a plurality ofimage transfer or digitizing systems for respectively digitizing each ofthe recorded images or frames of film or groupings of frames of film.Each image transfer and digitizing system comprises an illuminatorsystem for illuminating the respective frames or groupings of frames,and a system for characterizing the exposure conditions produced by theilluminator systems. Moreover, each image transfer and digitizing systemalso comprises a camera system for transferring the image of therespective frame or groupings of frames onto a linear, trilinear ormultidimensional CCD array, and digitizing the output of each of the CCDarrays. The camera sensor additionally comprises a position sensor fordetecting a first and a second pair of edges of a coordinated positionaltag. The coordinated positional tag itself comprises a sprocket hole atthe edge of the film frame. Further, each camera system comprises analigning mechanism for aligning each camera system in response to theset of edges of the respective coordinated position tag detected by theposition sensor. Finally, each camera system also comprises a digitizerand data feeder for feeding the respective CCD array outputs, the outputof the camera position sensor, the output of the system forcharacterizing the exposure conditions, and information gathered byother sensors on the state of the overall system to an external paralleldigital recording system.

In a further embodiment of the present invention, an illuminator systemfor illuminating a plurality of recorded images is disclosed. Theilluminator system comprises a first, second and third light sourcegenerating a first, second and third light beam. Further, theilluminator system comprises a first, a second and a third color filterfor colorizing the first, second, and third light beam respectively, aswell as an output lens system. The illuminator system moreover comprisesa coupling system for selectively coupling each of the first, second,and third light sources individually with the output lens system.

In still a further embodiment of the present invention, an illuminatorsystem for illuminating a plurality of recorded images is disclosed. Theilluminator system comprises a light source for generating an inputlight beam, a filter wheel comprising a first, a second and a thirdcolor filter, and a filter wheel motor for selectively coupling each ofthe first, second and third color filters individually with the inputlight beam, such that a first, a second and a third colorized light beamare individually generated. Additionally, the illuminator systemcomprises an output lens system and a coupling system for coupling eachof the first, second and third individually generated colorized lightbeams with the output lens system.

In still another embodiment of the present invention, an illuminatorsystem is disclosed for illuminating a plurality of recorded images. Theilluminator system comprises a set of sensors and color filters forrecording the exposure conditions of the illuminator system.

In yet another embodiment of the present invention, an alignment systemis disclosed for aligning each of a plurality of camera systems itsrespective image of a plurality of recorded images in a telecine. Thealignment system comprises a position sensor for detecting a first and asecond pair of edges of a sprocket hole tag of each recorded image ofthe plurality. Furthermore, the alignment system comprises an alignmentmechanism for aligning each of the camera systems with its respectiverecorded image of the plurality.

In yet another embodiment of the present invention, a calibration systemis disclosed for calibrating each camera sensor of the improved telecinerelative to one another. The calibrating system is employed forcalibrating a gray scale, a color scale, or a magnification scale of afirst camera sensor of a first digitizer with a second camera sensor ofa second digitizer. The calibration system comprises a test framecomprising at least one of a gray field reference pattern, a colorreference pattern, and a magnification reference pattern. By thisdesign, the first and second digitizers both digitize the same referencepattern from the test frame. Further, the calibration system alsocomprises a computer system for compensating for fluctuations in thegray scale, color scale, or magnification scale between the first camerasensor of the first digitizer and the second camera sensor of the seconddigitizer in response to the reference pattern of the test framedigitized by the first and second digitizers.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be better understood from reading thefollowing description of non-limited embodiments, with reference to theattached drawings, wherein below:

FIG. 1 illustrates a first embodiment of the present invention;

FIG. 2 illustrates a second embodiment of the present invention;

FIGS. 3(a) and 3(b) illustrates a top view and a cross sectional view ofa third embodiment of the present invention;

FIGS. 4(a) and 4(b) illustrates a top view and a cross sectional view ofa fourth embodiment of the present invention;

FIGS. 5(a), 5(b) and 5(c) illustrate a top view of two recorded imageson a film, and cross sectional views of a first and second component ofa fifth embodiment of the present invention, respectively; and

FIG. 6 illustrates a calibration scheme for calibrating the presentinvention.

It should be emphasized that the drawings of the instant application arenot to scale but are merely schematic representations and are notintended to portray the specific parameters or the structural details ofthe invention, which can be determined by one of skill in the art byexamination of the information herein.

BEST MODE FOR CARRYING OUT THE INVENTION

Prior U.S. application Ser. Nos. 09/036,347 and 08/384,998 are herebyincorporated herein by reference.

Referring to FIG. 1, a parallel telecine 10, or system for converting aplurality of recorded images or frames of film 12 to a respectiveplurality of digital data stream, is illustrated according to a firstembodiment of the present invention. As will become evident hereinbelow,parallel telecine 10 performs this image to digital data conversion in atwo phase parallel manner. This two phase parallel telecine design isintended to record several images simultaneously so as to achieve areduction in the time of digitizing a full length feature film. Further,while the focus of the present invention is on a colorized paralleltelecine, it should be apparent that a monochromatic system may bedevised utilizing the teachings of the invention detailed hereinbelow.

To realize this two phase parallel configuration, film 12 is defined bya first and a second set or grouping of frames. Corresponding to thefirst and second set are a first and a second digitizer, 14 and 16,respectively, incorporated in parallel telecine 10, such that eachdigitizer digitizes its respective set. In the preferred embodiment ofthe present invention, first and second digitizers each comprise aCharge Coupled Device ("CCD") and associated an analog to digitalconverter.

First and second digitizers, 14 and 16, each comprise an illuminatorsystem 18 for illuminating the plurality of frames within the respectiveset of frames of film 12 and a sensor camera 20 for digitizing therespective set and for generating a digital data output. Each sensorcamera 20 in turn comprises a position sensor and an aligning mechanism,both detailed hereinbelow and illustrated in FIGS. 5 and 6,respectively. The position sensor functionally detects a first, second,third and fourth edge of each coordinated positional tag, or sprockethole, associated with each frame of film 12. In response to detectingthe edges, the aligning mechanism aligns camera sensor 20 with respectto its respective frame of film 12.

By aligning each camera sensor 20 to its respective frame of film 12, incontrast with aligning each frame of film 12 with its respective camerasensor 20, several benefits are derived. Firstly, a cost savings isrealized as fewer multiple precision mechanical alignments componentsare required. Second, there is a substantial reduction in the risk ofdeforming the film, as well as the size of the telecine, by aligningcamera sensor 20 with respect to its respective frame of film 12. Thisis attributed to an otherwise significant amount of slack and/or idlerloops required between each camera of another parallel telecine design.In aligning the camera sensor 29 with the film 12, a reduction in thewear of the overall system is additionally realized in view of thereliance on sensors and aligners, as opposed to known telecine designswhich rely more heavily on the mechanical integrity of alignment pinsand sprocket holes. Moreover, by utilizing the position sensor andaligning mechanism of the present invention, proper image alignment maystill be achieved irrespective of damage to the sprocket holes.

Parallel telecine 10 also comprises a feeder 22 for feeding the firstand second sets of frames of film 12 into each of the first and seconddigitizers. Feeder 22 comprises several subcomponents including a filmsource reel 24, a film guider 26, a torque motor 28, a film positionsensor 30, an idler 32, and a film takeup reel 34.

In a further embodiment, parallel telecine 10 also comprises a datastorage system (not shown). The storage system functionally enablesarchiving of the digital data outputs from both digitizers.

Referring to FIG. 2, a parallel telecine 40 is illustrated according toa second embodiment of the present invention. Here, a parallel telecine40 comprises a first, second, third and fourth digitizer, 42, 44, 46,and 48, respectively, to realize a four phase parallel arrangement. Thismultiphase parallel telecine design is intended to record multipleimages simultaneously so as to achieve a substantial reduction in thetime of digitizing a full length feature film. In a further embodiment,one design for multiphase parallel telecine converts 24 imagessimultaneously to expedite digitizing the film.

Referring to FIGS. 3(a) and 3(b), an illumination system 50 isillustrated from a top and cross-sectional view according to a thirdembodiment of the present invention. Illumination system 50 functionallyilluminates recorded images or frames of film 12. While designed to beincorporated in a parallel telecine structure such as the arrangementdetailed hereinabove and illustrated in FIGS. 1 and 2, it should beapparent to one of ordinary skill in the art that illumination system 50has various other applications which require the illumination ofrecorded images.

Illumination system 50 comprises a first, a second and a third lightsource, 52, 54, and 56, for generating a first, second and third lightbeam, respectively, to sequentially illuminate each recorded image orframe of film with a red (R), green (G) or blue (B) light. Each R, G andB light beam illuminate a camera sensor which is read out to provide adata record. The data record comprises information regarding the red,green or blue color content of the respective recorded image or frame offilm. Light source, 52, 54, and 56 may comprise any lamp having asufficient intensity to allow the light beams to pass through the film.

In an alternate embodiment of the present invention, illumination system50 additionally comprises a light intensity detector 53 for detectingthe light intensity of the light beam of the relevant light source. Alight reflector 55 is also incorporated to reflect all misdirectedenergy back into the desired direction. Detector 53 serves twofunctional purposes. Firstly, it maintains a constant mean illuminationlevel throughout the length of the reel of recorded images or frames offilm. In response to the detected light intensity, a feedback controlloop (not shown) is included for adjusting the relevant light source'slight intensity accordingly. Moreover, detector 53 additionally providesa reference with respect to the exposure conditions of the illuminatorduring the telecine's operation. This information may be used once thefilm has been digitized to compensate for fluctuations in the operationof the illumination system 50.

Optically coupled with and corresponding to first, second and thirdlight sources, 52, 54, and 56, are a first, a second and a third colorfilter, 58, 60 and 62. Color filters, 58, 60 and 62, each comprise onecolor from the red, green, blue group to enable proper reformation ofthe image captured on the particular frame of film 12. As a result oftheir relationship with light sources 52, 54, and 56, color filters, 58,60 and 62 each generate a colorized first, second and third light beam.

In a further alternate embodiment of the present invention, each of thecolor filters comprises an infrared absorber (not shown). The infraredabsorber functionally absorbs excess infrared energy generated by therelevant light source to prevent damage to recorded image.

In still a further alternate embodiment of the present invention,illumination system 50 additionally comprises a color analysis detector64. Color analysis detector 64, in cooperation with a relevant colorfilter, detects the color quality of the emanating relevant light beam.Given the digital nature of the output results of the parallel telecine,fluctuations in the color quality may be compensated after film 12 isdigitized.

Illumination system 50 also comprises an output lens system. The outputlens system comprises several components, including a microopticillumination flattener 66, a collimating lens 68 and a diffuser 70.Microoptic illumination flattener 66 functionally flattens the colorizedlight beam input into the output lens system, while collimating lens 68collimates the colorized light beam flattened by the microopticillumination flattener 66. Finally, diffuser 70 diffuses the collimatedand flattened colorized light beam. It should be noted that microopticillumination flattener 66, collimating lens 68 and diffuser 70 may havealternate arrangements and positions relative to one another withoutimpacting on their functionality.

Furthermore, illumination system 50 comprises a coupling system forselectively coupling each color filter 62 with the output lens system.The coupling system comprises a scanning motor 72 for selectivelycoupling the output lens system with one of the color filters, 58, 60 or62. Further, the coupling system comprises an off-axis ellipsoidalmirror 72 for transmitting to the output lens system the colorized lightbeams generated by the color filter selectively coupled with the outputlens system. To realize this arrangement with the output lens system,scanner motor 74 rotates and repositions ellipsoidal mirror 72 betweencolors filters, and the resultant reflected beam is then directedtowards the output lens system.

Referring to FIGS. 4(a) and 4(b), an illumination system 90 isillustrated from a top and cross-sectional view according to a fourthembodiment of the present invention. Illumination system 90 functionallyilluminates recorded images or frames of film 12. While designed to beincorporated in a telecine structure such as the arrangement detailedhereinabove and illustrated in FIGS. 1 and 2, it should be apparent toone of ordinary skill in the art that illumination system 90 has variousother applications which require the illumination of recorded images.

Illumination system 90 comprises a light source 100 for generating alight beam to simultaneously illuminate a first and second recordedimage. As such, in the multiphase parallel telecine structure of FIG. 2,illumination system 90 is preferred. It should be noted, however, thatlight source 100 may be used to illuminate a single recorded image as inthe configuration of FIGS. 3(a) and (b).

In an alternate embodiment of the present invention, illumination system90 comprises a first and second light intensity detector 102(a) and102(b) for detecting the light intensity of the light beams of lightsource 100. Detectors 102(a) and 102(b) serve two functional purposes.Firstly, they maintain a constant mean illumination level throughout thelength of the reel of recorded images or frames of film. In response tothe detected light intensity, a feedback control loop (not shown) isincluded for adjusting the relevant light intensity of light source 100.Moreover, detectors 102(a) and 102(b) additionally provide a referencewith respect to the exposure conditions of the illuminator during thetelecine's operation. This information may be used once the film hasbeen digitized to compensate for fluctuations in the operation of theillumination system 90.

Coupled with light source 100 are filter wheels 104(a) and 104(b) andfilter wheel motors 106(a) and 106(b). Each of filter wheels 104(a) and104(b) comprise three filters, 105, 106, and 107, each of which compriseone color from the red, green, blue group to enable proper reformationof the images captured on the particular frames of film 12. Further,filter wheel motors 106(a) and 106(b) selectively couple light source100 with a filter from each filter wheel by means of a cold mirror103(a) and 103(b). Each cold mirror transmits the energy generated bylight source 100 to its respective filter wheel, while transmittingexcess infrared energy into safe parts of the illuminator away from thefilm. Further, each filter wheel motor rotates and repositions itscorresponding filter wheel into alignment with light source 100 suchthat a first, second and third colorized light beam are selectivelygenerated.

In a further alternate embodiment of the present invention, instead ofusing cold mirrors, each of the color filters comprises an infraredabsorber (not shown). The infrared absorber functionally absorbs excessinfrared energy generated by the relevant light source to prevent damageto recorded image.

In still a further alternate embodiment of the present invention,illumination system 90 additionally comprises a first and second coloranalysis detector, 110(a) and 110(b). Each color analysis detector, incooperation with each color filter, detects the color quality of theemanating relevant light beam. Given the digital nature of the outputresults of the telecine, fluctuations in the color quality may becompensated after film 12 is digitized.

Illumination system 90 also comprises a first and second output lenssystem. Each output lens system comprises several components, includinga microoptic illumination flattener 112, a collimating lens 114 and adiffuser 116. Microoptic illumination flatteners 112(a) and 112(b) eachfunctionally flatten the colorized light beam input into the output lenssystem, while collimating lenses 114(a) and 114(b) each collimate thecolorized light beam flattened by their respective microopticillumination flatteners 112(a) and 112(b). Finally, diffusers 116(a) and116(b) diffuse their respective collimated and flattened colorized lightbeams. It should be noted that microoptic illumination flatteners 112(a)and 112(b), collimating lens 114(a) and 114(b) and diffusers 116(a) and116(b) may have alternate arrangements and positions relative to oneanother without impacting on their functionality.

Furthermore, illumination system 90 comprises a first and secondcoupling system for coupling each of the first, second and third colorfilters with the output lens system. Each coupling system comprises afold mirror 118. Fold mirrors 118(a) and 118(b) both transmit one of thecolorized light beams to their respective output lens system.

Referring to FIG. 5(a), a top view of two recorded images or frames, 120and 122, are illustrated for the purposes of a fifth embodiment.Recorded images 120 and 122 are attached to a base film 124 and have apredetermined spacing. To facilitate its feeding within a telecine, aplurality of coordinated positional tags or sprocket hole tags 126 areincorporated in base film 124. Each sprocket hole tag of the pluralityhave a uniform size, rectangular shape, and uniformly spaced from eachother.

Referring to FIG. 5(b), a first component of an alignment system isillustrated. In operating any known parallel telecine structure, thepositioning of the recorded image relative to digitizing camera is ofcritical importance. As such, the alignment system comprises a positionsensor system 130 for detecting the position of the sprocket hole tag126, or more specifically, the X and Y coordinates of a first, second,third and fourth edge of the sprocket hole tag according to an X and Yaxis. It should be noted that with the coordinates of one edge detected,the remainder may be simply calculated, assuming each tag 126 has aknown size, shape and spacing. Additionally, the alignment systemcomprises an alignment mechanism 140, as shown in FIG. 5(c).

To detect the edges of the sprocket hole tag 126, position sensor system130 comprises a light source 132. Light source 132 generates a lightbeam 133 having a light intensity for illuminating each sprocket holetag 126. As a result of this configuration, the rear face of eachsprocket hole tag 126 is illuminated and a portion of light beam 133passes through each sprocket hole tag 126.

Position sensor system 130 further comprises a sensor camera 134,preferably a Charge Coupled Device ("CCD"). Functionally, sensor camera134 detects that portion of light beam 133 passing through the rear faceof each sprocket hole tag 126 and projected onto the sensor 134 itself.A portion of light beam 133, it should be noted, is not projected ontocamera 134 due to tag 126. In response to the portion of the light beamdetected by sensor camera 134 and that portion not projected onto camera134, the positions of the four edges of each sprocket hole tags aredetected by a system (not shown) for determining the edge coordinatesbasing its calculations on transitions in the detection of light.

In an alternate embodiment of the present invention, position sensorsystem 130 further comprises an optical lens system 134 for directs andprojects the portion of light beam 133 passing through tag 126 at lightintensity detector 136.

Referring to FIG. 5(c), alignment mechanism 140 is illustrated from across-sectional view. Alignment mechanism 140 functionally alignsdigitizing camera 142 relative to recorded image 120 in view of thefirst and second edges detected by position sensor 130. This is realizedby incorporating a first and second translating mechanism, 144 and 146.First translating mechanism 144 configures digitizing camera 142 withrespect to recorded image 120. Further, second translating mechanism 146positions a lens structure 148 relative to the digitizing camera 142.

In an alternate embodiment, the alignment system incorporates both afocus adjustment device (not shown) for focusing each recorded image anda magnification adjustment device (not shown) for magnifying eachrecorded image.

Referring to FIG. 6, a Digital Archive Calibration Frame ("DACF") 150 isillustrated. DACF 150 is functionally incorporated for the purpose ofcalibrating each camera sensor relative to one another during thedigitization process detailed hereinabove. Practically, a first set ofDACFs 150 are positioned at the beginning of the film reel, and a secondset at the end of the film reel. Each DACF in each set is read by eachcamera sensor so as to calibrate different aspects of the telecineduring the digitization process. By this arrangement, fluctuations inthe gray or color scale between cameras are detected using a group ofpatterns on DACF 150 and compensated for accordingly once digitizationof the film is completed. Similarly, fluctuations in the framemagnification between cameras are also detected using a further group ofpatterns on DACF 150. To simplify the process of making the first andsecond DACFs, in the preferred embodiment, the patterns required forcalibrating gray scale, color scale and magnification are allincorporated on a singular DACF and are further detailed below.

Each DACF 150 comprises a series of flat gray level fields 152, as wellas a continuous gray level field 154. Both series of fields 152 andcontinuous field 154 are employed to calibrate any variation in the grayscale between parallel telecine cameras. This is realized by detectingthe fields using the parallel telecine structure detailed hereinabove,and comparing this data once digitized with digitized data of anothertelecine camera. By this arrangement, fluctuations can be compensatedfor accordingly.

In the preferred embodiment of the present invention, to further assistthe series of fields 152 and the continuous field 154, additionalcalibrating frames (not shown) are also employed prior to and inconjunction with the first and second sets of DACFs 150. To providefurther support in calibrating the film to be digitized, theseadditional calibrating frames comprise a first and second test frame(not shown). The first test frame comprises a black level or zerotransmissivity, and a second test frame comprises a reference grayscale, or approximately 50% transmissivity.

Additionally, each DACF 150 also comprises a R-G-B color referencegrouping 156. As with both series of fields 152 and continuous field154, color reference grouping 156 is employed to calibrate variation inred, green or blue colors between parallel telecine cameras andcompensate for DC drift. This is realized by detecting the each color ofcolor reference grouping 156 using the parallel telecine structuredetailed hereinabove, and comparing this data once digitized withdigitized data of another telecine camera. Again, by this arrangement,fluctuations can be compensated for accordingly.

To insure that the magnification of each telecine camera is calibratedwith each other from reel to reel of the film, each DACF 150 furthercomprises a magnification pattern set 158. Magnification pattern set 158includes four circular patterns. Each circular pattern of set 158comprises a series of non-intersecting, enclosed circles each having adiameter. Each circle from the series of circles is uniformly spacedapart from an adjacent circle(s) such that each diameter of each circleis reduced by a uniform distance relative to an adjacent circle.However, the uniform spacing or distance of each circle of the seriesare distinct from all other patterns of set 158.

With each pattern having a distinct spacing arrangement, a twodimensional Fast Fourier Transform ("FFT") may then be performed by acomputer (not shown) to properly calibrate the magnification of eachcamera relative to each other. Executing an FFT on each pattern resultsin a circle having a single diameter for each pattern. This singlediameter is a proportional representation to the spacing between circlesof the relevant pattern of set 158. With the size of the circle of apattern of set 158 determined, the singular diameter can be measuredaccordingly using a scanning system or computer.

It should be noted that alignment check fiducials 160 and aperture cropguides 162 are also employed on each DACF 150. Fiducials 160 and guides162 are both incorporated to assist in aligning the relevant frame withrespect to the relevant camera.

Moreover, it should be also noted that the present invention, as statedherein, enables the correction of errors and flaws in the state of therecording equipment, the illuminator, exposure conditions, color qualityand the state of the film during post processing. Various means areavailable that will realize this embodiment including a simple computercapable of tracking through the various data derived through thedigitization process. Similarly, a table of correction data may beassembled during or after the digitization process to assist thecomputer in compensating and correcting the digitized data.

It should be noted that in another embodiment of the present invention,the calibrating system calibrates a gray scale, color scale, ormagnification scale of a first camera sensor of a first digitizer with asecond camera sensor of a second digitizer. By this design, the firstand second digitizers both digitize the same reference pattern from theDACF. Further, the calibration system also comprises a computer system(not shown) for compensating for fluctuations in the gray scale, colorscale, or magnification scale between the first camera sensor of thefirst digitizer and the second camera sensor of the second digitizer inresponse to the reference pattern of the test frame digitized by thefirst and second digitizers. In a further embodiment, a data storagemeans (not shown) is also incorporated for storing the reference patterndata digitized by both the first and second digitizers.

While the particular invention has been described with reference toillustrative embodiments, this description is not meant to be construedin a limiting sense. It is understood that although the presentinvention has been described in a preferred embodiment, variousmodifications of the illustrative embodiments, as well as additionalembodiments of the invention, will be apparent to persons skilled in theart upon reference to this description without departing from the spiritof the invention, as recited in the claims appended hereto. Thus, whilea two phase parallel telecine is detailed herein, it should be apparentthat a multiphase parallel telecine can similarly be derived using theteachings herein. It is therefore contemplated that the appended claimswill cover any such modifications or embodiments as fall within the truescope of the invention.

All of the U.S. Patents cited herein are hereby incorporated byreference as if set forth in their entirety.

What is claimed is:
 1. A calibration system for calibrating at least oneof a gray scale, a color scale, and a magnification scale of a firstcamera sensor of a first digitizer with a second camera sensor of asecond digitizer, said calibration system comprising:a test framecomprising at least one of a gray field reference pattern, a colorreference pattern, and a magnification reference pattern; said firstdigitizer for digitizing said at least one of a gray field referencepattern, a color reference pattern, and a magnification referencepattern; said second digitizer for digitizing said at least one of agray field reference pattern, a color reference pattern, and amagnification reference pattern; and a computer system for compensatingfor fluctuations in said at least one of said gray scale, said colorscale, and said magnification scale between said first camera sensor ofsaid first digitizer with said second camera sensor of said seconddigitizer in response to said at least one of a gray field referencepattern, a color reference pattern, and a magnification referencepattern digitized by said first and second digitizers.
 2. Thecalibration system of claim 1, further comprising:data storage means forstoring said at least one of a gray field reference pattern, a colorreference pattern, and a magnification reference pattern digitized bysaid first and second digitizers.
 3. The calibration system of claim 1,wherein said first digitizer digitizes a first portion of a plurality ofrecorded images and said second digitizer digitizes a second portion ofsaid plurality of recorded images.